title: Photogeneration of metastable side-on N2 linkage isomers in [Ru(NH3)5N2]Cl2, [Ru(NH3)5N2]Br2 and [Os(NH3)5N2]Cl2.
abstract: Photogeneration of side-on N2 linkage isomers in [Ru(NH3)5N2]2+ and [Os(NH3)5N2]2+ is achieved by irradiation with lambda = 325 nm of powder samples at T = 80 K and detected by the downshift of the nu(N-N) vibration and by the heat release at elevated temperature due to the back switching of the side-on configuration to the ground state. The concentration of the transferred molecules is evaluated by the decrease of the area of the nu(N-N) or 2nu(N-N) vibrational bands. All characteristic changes between the linear Ru-N-N and side-on configuration are predicted by DFT calculations: the structure of the anion, shifts of the vibrations, electronic excitation energy, energetic position and sequence of the electronic orbitals, the potentials of the ground and relaxed metastable state with the activation energy, saddle points and energetic position of the minimum.
authors.affiliation: I. Physikalisches Institut, Universität zu Köln, Zülpicherstrasse 77, 50937, Köln, Germany. dominik.schaniel@uni-koeln.de
authors.forename: Dominik
authors.initials: D
authors.lastname: Schaniel
authors.forename: Theo
authors.initials: T
authors.lastname: Woike
authors.forename: Bernard
authors.initials: B
authors.lastname: Delley
authors.forename: Colette
authors.initials: C
authors.lastname: Boskovic
authors.forename: Hans-Ueli
authors.initials: HU
authors.lastname: Güdel
mesh_terms: D002152:Calorimetry, Differential Scanning; D003198:Computer Simulation; D007536:Isomerism; D008024:Ligands; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D017892:Osmium Compounds / Q000737:chemistry* / Q000378:metabolism*; D010777:Photochemistry; D017975:Ruthenium Compounds / Q000737:chemistry* / Q000528:radiation effects*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014466:Ultraviolet Rays; D014732:Vibration
chemical_list: D008024:Ligands; D017892:Osmium Compounds; D017975:Ruthenium Compounds; C533684:pentaammine(dinitrogen)osmium(II); C533683:pentaammine(dinitrogen)ruthenium(II); D009584:Nitrogen